Association between remnant cholesterol inflammation index and handgrip strength in maintenance hemodialysis patients

This study examined the association between the remnant cholesterol inflammation index (RCII) and handgrip strength in patients receiving maintenance hemodialysis (MHD).

This single-center cross-sectional study included 117 maintenance hemodialysis patients. Baseline characteristics, laboratory variables, and maximal handgrip strength were collected. Remnant cholesterol (RC) was calculated as total cholesterol minus LDL-C minus HDL-C, and RCII was calculated as [RC (mg/dL) × hs-CRP (mg/L)]/10. Because RCII was markedly right-skewed and included three verified negative calculated values, negative values were truncated to zero and ln(RCII + 1) was used as the primary exposure. The fully adjusted linear regression model included sex, age, BMI, creatinine, triglyceride, fasting plasma glucose, and albumin. Sensitivity analyses evaluated alternative treatments of negative and extreme RCII values, and restricted cubic spline analysis assessed potential non-linearity.

In the fully adjusted complete-case model (N = 116), each 1-unit increase in ln(RCII + 1) was associated with a 1.585-kg lower handgrip strength (B = -1.585, 95% CI -2.790 to -0.379; P = 0.010). The coefficient remained negative after excluding negative RCII values, using the original RCII scale, truncating negative values to zero, excluding extreme values, and fitting Huber robust regression. Statistical significance was attenuated after P1-P99 and 1.5×IQR exclusions. RCS analysis showed a significant overall association (P = 0.019) without evidence of non-linearity (P = 0.245).

Higher ln(RCII + 1) was associated with lower handgrip strength in maintenance hemodialysis patients after adjustment for seven clinically relevant covariates. The inverse direction was broadly consistent across sensitivity analyses, although estimates were less precise after excluding upper-tail RCII observations.